Water Quality

 

            This worksheet is designed to get you thinking about how the quality of water can be impacted and how changes in water quality can in turn, impact the organisms that depend on the water for life.  You will be on your own to locate websites that contain the information that you need, so have fun looking for interesting websites and remember to write down the web addresses that you use.  Use ‘Google’ to get started, just do a search for water quality parameters and start checking out websites.

 

  1. There are many factors that impact water quality and we will be measuring the ones listed below when we take our field trip.  Your group will choose one of the following factors and describe the following: 1) the factor-what amount is fine for the water and at what point does it become a pollutant/problem, 2) the source(s) of the pollutant, 3) the impact that it has on the organisms in the water. You will make a brief presentation (PowerPoint) and type up a sheet of the information you have collected to be distributed to your classmates.

 

Temperature

 

 pH

 

Phosphorus

 

Nitrate (Nitrogen)

 

Dissolved Oxygen

 

Turbidity

 

            Conductivity

 

            Fecal coliform

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Water Quality Sampling Procedure

 

We will be sampling the water quality of the Licking River using various parameters that are considered to be important in assessing the health of an aquatic ecosystem.

 

The first parameter that should be collected is the turbidity of the water.  To measure the turbidity we will be using the secchi disk.  Have one person holding the end of the rope attached to the secchi disk while it is being lowered into the water.  Another person is in charge of determining the turbidity using the following steps:

  1. Stand in the shade or with the sun at your back
  2. Position yourself so you are looking directly down at the Secchi disk while it is in the water
  3. Slowly lower the disk until the white areas just disappear and mark the spot where the rope meets the water (hold this spot with your fingers)
  4. Carefully raise the disk until the white area just becomes visible and again mark with your finger
  5. Form a loop with the excess line between your fingers and move one finger to the end of the loop.  This is the average light penetration reading or turbidity reading.
  6. Record this number

 

We will be sampling at 3 points in the water column: 1) surface, 2) middle 3) bottom.  The data we will gather for each sample is exactly the same and therefore each group should follow the methods presented as closely as possible.  Establish one group as surface, one as middle and one as bottom. 

 

Surface Group

      Your job will be to sample the surface water and to collect a plankton sample.  First collect a water sample by gently submerging a sample bottle (with the mouth up) until the bottle is ¾ full.  Remove the bottle from the river and set it on a level surface.  Using the appropriate probe determine and record the following data:

  1. Temperature
  2. pH
  3. Dissolved oxygen
  4. Nitrate
  5. Conductivity

 

Once you have recorded all of the above data, place a cap on your bottle and be sure the bottle is labeled correctly.

Now, take the plankton net and make sure the collection bottle is securely attached.  Take the net and throw it into the river making sure to hold tightly to the end of the rope!  Gently, but quickly, tow the net in keeping it as close to the surface as possible.  When it is near the shore pull up on the rope so the collection bottle will not spill its contents and remove from the water.  Carefully unscrew the collection bottle and pour the contents into the sample vial for the plankton.

 

 

Middle Water

 

      You will be using one of the deep water samplers to collect water from the middle of the water column.  First you will need to determine the depth of the water.  Carefully lower the deep water sampler into the water column and continue lowering it slowly until you feel it hit the bottom.  Mark the point where the rope and the surface of the water meet with your fingers and draw the sampler back to the surface.  Mark the point on the rope that is halfway between the sampler and your fingers—this is your sampling depth. Now:

1)      Close the wiffle balls on each end of the sampler and place the pin in the hole

2)      Carefully begin lowering the sampler into the water

3)      When you reach your mark, stop

4)      Make sure you are holding the sampler vertically in the water column and double check your mark

5)      Now, give a quick tug on the rope—DO NOT pull too hard or you will cause the sampler to be raised in the water, you only want to pull hard enough to remove the pin from the sampler

6)      Slowly raise the sampler to the surface and bring it onshore

7)      Put a sample bottle under the tube with the clamp and release the clamp.  You should collect enough water to fill the bottle ¾ full.

Once the sample bottle is full, bring it over to the probes and collect the following data:

1.      Temperature

2.      pH

3.      Dissolved oxygen

4.      Nitrate

5.      Conductivity

Once you have finished taking the above data, place the cap on the bottle—we will be bringing this sample back to campus.

 

Bottom Group

 

            You will be sampling the water just above the bottom of the river using the deep water sampler. 

1)      Close the wiffle balls on each end of the sampler and place the pin in the hole

2)      Carefully begin lowering the sampler into the water

3)      When you reach the bottom, stop

4)      Make sure you are holding the sampler vertically in the water column and slowly raise the sampler a couple of inches

5)      Now, give a quick tug on the rope—DO NOT pull too hard or you will cause the sampler to be raised in the water, you only want to pull hard enough to remove the pin from the sampler

6)      Slowly raise the sampler to the surface and bring it onshore

7)      Put a sample bottle under the tube with the clamp and release the clamp. You should collect enough water to fill the bottle ¾ full.

 

 

Once the sample bottle is full, bring it over to the probes and collect the following data:

1.      Temperature

2.      pH

3.      Dissolved oxygen

4.      Nitrate

5.      Conductivity

Once you have finished taking the above data, place the cap on the bottle—we will be bringing this sample back to campus.

 

 

 

Back on Campus:

 

            We will be doing 2 more activities back at the lab.  The first is simply to observe whether there are any plankton in our water sample.  Plankton are microscopic plants and animals that live in the water.  The plants (phytoplankton) are only found as deep as the light penetrates because they are dependent on the sun to conduct photosynthesis.  The animals (zooplankton) are generally found in the same area because they feed on the plants.  So, gently swirl the sample bottle of plankton and pour out some into an empty petri dish.  Place the dish under the dissecting microscope and see if you can find any plankton.  You may not find any depending on the time of year the sampling occurs.

 

            Next you will be setting up the fecal coliform analysis. 

 

PROTOCOL FOR COLIFORM COUNTS

 

Purpose: Dilution of the samples to produce small enough numbers on a plate so that reliable colony counts can be made.

 

 

ITEM

Dilution

Source

R O Water

Amount to be Filtered

1.

10%

50 mL of Sample

450 mL

200 mL

2.

1%

50 mL of Item 1

450 mL

200 mL

 

Item 1: 50 mL of sample is mixed to make 500 mL.

 

Item 2: 50 mL of Item 1 is diluted to make 500 mL which results in a dilution of 1/100 or 1%.

 

Note that the water quality standard is stated in colonies/100 mL of the original sample concentration. (http://water.nr.state.ky.us/ww/ramp/rmtests.htm)